Carburetor for internal combustion engines



Aug. 25, 1942. M. MALLORY 2,293,842

CARBURETOR FOR INTERNAL COMBUSTION ENGINES Filed Oct. 14, 1940 INVENTOR.MARON MALI-CRY /Wnw. W

ATTORNEYS.

Patented Aug. 25,-1 942 UNITED STATES PATENT OFFICE Marion Manor-y,Detroit, Mich.

Application mm- 14, 1940, Serial No. 361,022

6 Claims. (01. 261-65) This invention relates to a carburetor for aninternal combustion engine and in particular to a carburetor for a highspeed and high compression en ine.

The invention contemplates a carburetor having an intake passageway orthroat of sufflcient size or cross section so that the engine can mentedby thepull that diaphragm l3 exerts on arm Il to overcome or counteractthe push that spring I] exerts against arm-I I.

The operation of the device is as follows:

Assuming that theengine' is idling, the fixed collar 8 on throttle rodIII is held firmly against slidable collar I by spring 5 reactingagainst collar 6. When air valve 2 is a balanced valve or only veryslightly unbalanced then as the throttle rod I0 is moved towards an openposition, i. e., toward the left as viewed inFig. 1, collar .6compresses the spring 5 against the slidable collar 1 which is fastenedto the throttle shaft. arm 3. Therefore, it can be seen that spring5acting through pin l2 and arm ll tends to compress the spring ll in thesuction device taken in by the engine at all speeds to maintain anapproximately predetermined. high compression without knocking. V

In the drawing the figure is a vertical cross section through acarburetor showing the throttle valve control.

Referring more particularly to the drawing, the carburetor comprises ahousing having an air inlet 2| and fuel air mixture outlet 22. Theintake passageway or throat of the carburetor is designated M. Thecarburetor is provided with the usual venturi 23 and fuel nozzle 9.

Y The throttle valve 2 is fixed upon the shaft 4 journalled in thehousing 20. Valve 2 may be when the throttle is opened. These twosprings,

.are so balanced that spring 5' cannot compress spring I] enough to open.the throttle very wide,

but, as the engine speed increases, the air fiowing through the venturicreates a suction at orifice I, which is imposed on diaphragm l3 andeither balanced or unbalanced. Preferably, as

shown, valve 2 is an unbalanced valve.

' A lever 3 is fixed upon the throttle valve shaft 4 and is pivotallyconnected to collar I which is slidably mounted upon the throttle rodl0.-

Throttle rod I0 i a push and pull rod and has fixed thereon the spacedcollars 6 and 8. Slidable collar I is positioned on rod Ill betweencollars 6 and 8 and backed up by coil spring 5. Lever 3 has a lostmotion connection with arm H in the form of a pin l2 fixed on lever 3which engages arm II in the elongated slot 24. The

other end of arm ll is fixed to the diaphragm l3.

enclosed in the housing It. Chamber I8 in the housing I6 is closed toatmosphere except through conduit l5 which communicates with the venturipassageway 23 through orifice I.

A coil compression spring ll backs up the diaphragm l3 in the chamberl8. Compression spring I! tends to hold the diaphragm and rod II towardthe left and thereby hold throttle valve 2 closed. Spring 5 is also acompression spring but weaker than spring II. The force exerted byspring 5 against collar 1 is suppletends to assist spring 5 incompressing spring l1. As the engine speed increases, the suctioncreated by the air flow through the venturi tends to move the diaphragmarm I I back or towards the right away from pin l2 so that spring 5 willcause the throttle valve 2 to move or swing open. Eventually the enginspeed will be high enough so that the Venturi suction will be highenough to move the diaphragm arm far enough towards the right so thatspring 5 is free to move the throttle valve completely open.

The throttle valve 2 'is shown slightly unbalanced. In this case it isnot necessary to use spring 5 to assist the opening of the throttlevalve and spring 5 can be omitted. If the valve is unbalanced, thevacuum between it and the engine will tend to open it against spring IIas soon as the collar 8 is moved away from the sliding collar I by themovement of the throttle rod Ill. Of course, if a balanced valve isused, it will be necessary to use spring 5 to start its opening.Regardless whether valve 2 is balanced or unbalanced, sufiicient chargewill flow by valve 2 when closed to idle the engine.

Iclaim:

1. In combination with a carburetor for an internal combustion enginehaving an intake passageway provided with a venturi, a throttle valve insaid passageway on the engine side of said venturi, resilient meanstending to close said throttle valve, manually operated primary meanstending to, open the throttle valve and weaker than the above saidresilient means for closing the valve, said manually operated primarymeans having a positive connection with the throttle valve forcompletely closing the same to idle the engine, and a suction devicecommunicating with the venturi and applying a force against the saidresilient means which force increases in magnitude as the speed of theair flowing through said venturi increases, said suction devicesupplementing said primary means to overcome said resilient means andopening the throttle valve as the speed of the air flowing through theventuri increases.

2. In combination with a carburetor for an internal combustion enginehaving an intake passageway provided with a venturi, an unbalancedthrottle valve in said intake passageway on the engine side of theventuri and tending to open due to the vacuum on the engine sidethereof, resilient means tending to close said throttle valve and forholding the same closed when the engine is idling, and a suction devicecommunicating with the venturi and applying a force against the saidresilient means which force increases in magnitude as the speed of theair flowing through said venturi increases, said suction devicesupplementing the unbalanced pressures on the unbalanced throttle valvetending to open the same and for overcoming said resilient means andopening the throttle valve as the speed of the air flowing through theventuri increases.

3. In combination with a carburetor for an internal combustion enginehaving an intake passageway provided with a venturi, a throttle valve onthe engine side of the venturi, manually operated means having a lostmotion connection with the throttle valve for opening the same and apositive connection with the throttle valve for completely closing thesame to idle the engine, resilient means tending to close said throttlevalve, a primary means controlledby said manually operated means andweaker than said resilient means tending to open the throttle valve whenthe manually operated means are moved in a throttle opening direction,and a suction device communicating with said venturi and responding tothe vacuum created by the flow of air through the venturi forsupplementing the said primary means with a force which increases inmagnitude as the speed of the air flowing through the venturi increasesto overcome said resilient means and open the throttle valve as thespeed of the air flowing through the venturi increases. v

4. In combination with a carburetor for an internal combustion enginehaving an intake passageway provided with a venturi on the atmosphereside of the throttle, a throttle valve, manually operated means having ast motion connection with the throttle -valve'for opening the same, anda positive connection with the throttle valve for completely closing thesame to idle the engine, a spring tending to close said throttle valve,9. spring weaker than said flrst mentioned spring tending to openthethrottle valve when the manually operated means are moved in a throttleopening direction, and a suction device communicating with said venturiand responding to the vacuum created by the flow 01' air through theventuri for supplementing th weaker spring to overcome said strongerspring and open the throttle valve as the speed of the air flowingthrough the venturi increases.

5. In combination with a carburetor for an internal combustion enginehaving an intake passageway provided with a venturi on the atmosphereside of the throttle, a throttle valve in the intake passageway, amanually operated push and pull member, a pair of spaced stops on saidmember, a connection between the throttle valve and said push and pullmember movable between said stops, a spring positioned between one ofsaid stops and said movable connection tending to open the valve whenthe push and pull member is moved in a throttle valve opening direction,a spring relatively stronger than the aforementioned spring tending toclose said throttle valve, and a suction device communicating with thesaid venturi and responding to the flow of gas through the venturi tosupplement the action 01' the weaker spring to overcome the strongerspring and open the throttle valve commensurately with the increase inthe speed of the air flowing through said venturi.

6. In combination with a carburetor foran internal combustion enginehaving an intake passageway provided with a venturi on the atmosphereside of the throttle, a throttle valve, manually operated means having alost motion connection with the throttle valve for opening the same anda positive connection with the throttle valve for completely closing thesameto idle the engine. a spring tending to close said'throttle valve,pressure means acting on said throttle valve when the manually operatedmeans are moved in throttle opening direction and acting against saidspring to partially open said throttle valve, and a suction devicecommunicating with said venturi and responding to the vacuum created bythe flow of air through the venturi for supplementing the said pressuremeans to overcome said stronger spring and open the throttle valvefurther as the speed of the air flowing through the venturi increases.

MARION MALLORY.

